EOTI / eWTI, digital oil and winding temperature indicators with Modbus RTU
eOTI and eWTI are digital oil and winding temperature indicators for power transformers and reactors, with a dial gauge and built-in electronics. Accuracy is 1.5 % of the upper range limit, with up to six microswitches, a 4–20 mA output and RS485 Modbus RTU.
- Standards
- IEC 60076-22-1, JB/T 6302-2005
- Ranges
- 0…+120, 0…+150, 0…+160, 0…+180, −50…+150, −20…+140 °C
- Accuracy
- 1.5 % of upper range limit (measurement and contact switching)
- Microswitches
- up to 6
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
Oil and winding temperature is directly linked to insulation aging, so on a transformer it is monitored both locally and from the control room. The eOTI (oil) and eWTI (windings) combine a proven manometric system with a Bourdon tube and a dial gauge with electronics that pass the measured value to the upper level. The operator sees the reading at the unit, the monitoring system receives data continuously, and the substation can be moved to condition-based maintenance.
The scales are made for 0…+120, 0…+150, 0…+160, 0…+180, −50…+150 and −20…+140 °C. The measurement and contact switching error is 1.5 % of the upper range limit. Up to six microswitches control the cooling stages, give an alarm and a trip command, and the setpoints are adjusted on site or at the factory during assembly. The outputs are an analog 4–20 mA, optionally PT100, and a digital RS485 Modbus RTU. The supply is 24 V DC ±10 % with correct polarity, and consumption is 1.5 W.
The IP66 enclosure has up to three M25×1.5 cable glands and two vent valves against condensation, with a single valve on the compact type. The capillary is made of Rilsan or stainless steel, and the bulb of copper or stainless steel. The capillary is protected by a stainless sleeve in the standard version or made of copper in a Rilsan sheath. The window is polycarbonate, laminated or tempered glass. The ambient temperature is from −40 to +70 °C. The instruments comply with IEC 60076-22-1 and the Chinese JB/T 6302-2005.
The same built-in outputs are provided on the compact eOTI-C and eWTI-C for cabinet mounting, and for the ANSI market the eATI and eAWTI are made. The indicators belong to the eDevices family, work with third-party devices and connect to a central control unit. In the MeDICA ecosystem the temperature data goes into thermal models for assessing insulation aging. The instruments are fitted to power transformers and reactors, in smart grid networks, at offshore and tropical sites, in new installations and in place of mechanical thermometers during substation digitalization.
Technical specifications
| Standards | IEC 60076-22-1, JB/T 6302-2005 |
|---|---|
| Ranges | 0…+120, 0…+150, 0…+160, 0…+180, −50…+150, −20…+140 °C |
| Accuracy | 1.5 % of upper range limit (measurement and contact switching) |
| Microswitches | up to 6 |
| Outputs | 1 × 4–20 mA; 1 × PT100 (option); RS485 Modbus RTU |
| Supply | 24 V DC ±10 %, 1.5 W |
| Degree of protection | IP66 |
| Ambient temperature | −40…+70 °C |
| Capillary | Rilsan or stainless steel; bulb copper or stainless steel |
Request a price and lead time
EOTI / eWTI, digital oil and winding temperature indicators with Modbus RTU. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 9025 19 20 00 |
|---|---|
| HS, 6 digits | 9025 19 |
| CN (EU) | 9025 19 20 |
| HTSUS (USA) | 9025 19 80 10 |
| China customs tariff | 9025 19 90 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
Which scale ranges are available for the eOTI and eWTI?
The scales are 0…+120, 0…+150, 0…+160, 0…+180, −50…+150 and −20…+140 °C. The measurement and contact switching error is 1.5 % of the upper limit.
How do the eOTI and eWTI send data to SCADA?
Through the 4–20 mA analog output and the digital RS485 Modbus RTU, with a PT100 output optionally available. The device supply is 24 V DC ±10 %.
Which standards do the indicators comply with?
IEC 60076-22-1 and the Chinese JB/T 6302-2005. The enclosure degree of protection is IP66, and the ambient temperature is from −40 to +70 °C.
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